Soil pH in Ontario, NY: Lime or Sulfur?

Typical topsoil pH in Ontario, NY

Typical topsoil in Ontario, NY is pH 6.39, already right for vegetable garden (6-7). Test before adding anything.

What Ontario needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Sulfur: potatoes 2.1 lb/100 sq ft over 2 applications; blueberries 3.2 lb/100 sq ft over 2 applications; azaleas and rhododendrons 2.5 lb/100 sq ft over 2 applications; blue hydrangeas 2.5 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.39, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 403,183 surveyed acres in Ontario, NY, 43% are near neutral (6.5-7.3), 35% are moderately acidic (5.5-6.5), 16% are strongly acidic (below 5.5), 5% are alkaline (above 7.3). Mapped soils run from pH 4.8 to 8, a spread of 3.2 units across 771 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.

Clay, organic matter and rates

Topsoil here averages 19.3% clay and 4.87% organic matter, which this site treats as loam. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. 3% of mapped components carry free carbonate (lime already in the ground).

Ontario against the rest of New York

pH 6.39 is 0.62 above the New York median of 5.77. 55 of 62 New York counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Orleans (6.28), Montgomery (6.29), Richmond (6.31), Niagara (6.34), Seneca (6.42), Genesee (6.43), Bronx (6.51), New York (6.91).

The range in New York runs from Hamilton at 4.72 to Kings at 7.15; Ontario sits 69% of the way up.